PdfDocumentOptionsOutlineHeadingSelectors Property

The CSS selectors of the elements that become bookmarks of the document outline, one selector for each level: the first selector gives the level 1 bookmarks, the second one the level 2 bookmarks and so on, up to level 6. When this property is set the H1 to H6 headings and the data-heading attribute no longer select the bookmarks, an element still being excluded with data-heading="false" and its title still being taken from data-heading-text when present. The selectors are honored in custom mode when UseBrowserOutlineMode is false. The default is null, the bookmarks being created from the headings of the document

public string[] OutlineHeadingSelectors { get; set; }